1. Field of the Invention
The present invention relates to an ultrasonic diagnosis device, an ultrasonic image analysis device, and an ultrasonic image analysis method, and more particularly, to an ultrasonic diagnosis device, an ultrasonic image analysis device, and an ultrasonic image analysis method that can generate and display parameter image data based on motion parameters of myocardium and the like by analyzing ultrasonic image data collected from a sample.
2. Description of the Related Art
An ultrasonic diagnosis device radiates ultrasonic pulses generated from a vibrating element built in an ultrasonic probe into a sample, receives reflected ultrasonic waves resulting from a difference in acoustic impedance between sample tissues by the use of the vibrating element, and then displays the received ultrasonic waves on a monitor. This diagnosis method is widely used for shape diagnosis or function diagnosis of biological organs, since the method can allow real-time two-dimensional image data to easily be observed with a simple operation of bringing the ultrasonic probe into contact with a simple surface.
An ultrasonic diagnosis method of acquiring biological information by the use of ultrasonic waves reflected from tissues or globules in a biological sample has been rapidly developed with the development of two techniques of an ultrasonic pulse reflecting method and an ultrasonic Doppler method. The observation of B-mode image data or color Doppler image data obtained by the techniques is essential to today's ultrasonic image diagnosis.
In recent years, a strain imaging method of two-dimensionally observing “strains” on the basis of motion velocity information of myocardial tissues which could be acquired by analyzing ultrasonic image data such as B-mode image data was attempted.
In the strain imaging method for the function diagnosis of a heart, B-mode image data are collected in time series on the basis of received signals acquired by the scanning of ultrasonic waves on a sample and a tracking process using the pattern matching is performed on ultrasonic image data temporally adjacent to each other to measure “displacements” of parts of the myocardial tissues. Then, by calculating a two-dimensional distribution of the “strains” defined as a displacement per unit length, strain image data are generated.
There was also suggested a method of measuring the two-dimensional distribution of “strain velocity” from the spatial gradient of the motion velocity acquired by a tissue Doppler imaging (TDI) method of two-dimensionally displaying the motion velocity of the myocardial tissues by adapting the color Doppler method and temporally integrating the “strain velocity” to generate the strain image data (for example, Japanese Unexamined Patent Application Publication 2005-130877).
The time-series strain image data acquired by the use of the strain imaging method are overlapped with the ultrasonic image data such as B-mode image data used to generate the strain image data and are displayed as moving images on a monitor as a display unit.
In the recent ultrasonic diagnosis in the field of the heart, it became clear that the cardiac disorder could be early diagnosed by observing in detail parameter image data such as strain image data at a predetermined time phase of the initial diastole.
When the parameter image data at the predetermined time phase of the initial diastole are selectively observed, it was difficult to accurately observe the “strain” of the myocardial tissues at the predetermined time phase from the parameter image data continuously displayed as the moving images like the past.
Since it is necessary to use an end systole of the myocardial tissues as a reference to accurately setting the predetermined time phase, it was difficult to accurately set the predetermined time phase in the methods based on the end systole specified by R-wave timing of the electrocardiographic waveforms like the past.